Using Scales

This is a preview of the educational program A Jazz Improvisation Almanac which is under development for the Outside Shore Music Online School. Feel free to browse this preview and learn what you can from it. For a more completed product, though, check out the original freely browsable jazz textbook, A Jazz Improvisation Primer.

The previous section demonstrated that any note of the chromatic scale can be related to any chord. This would seem to imply that an improvising musician is free to choose any note at any time. However, the previous section also showed that some combinations of notes and chord are more dissonant than others, and we noted that musicians generally try to balance tension and release. Furthermore, we observed that diatonic notes tend to be more consonant against unaltered chords, and altered notes tend to be more consonant against altered chords.

Rather than attempting to keep all this in mind in selecting notes to use over a given chord, jazz musicians often use a variety of scales as a way of generating appropriate note choices. In tonal music, the most important factor in selecting a scale is function. The scale should generally contain the root, third, and seventh of the corresponding chord. The simplest example is the C major scale, which is an appropriate scale to play over a Cmaj7 chord, as it contains all of the chord tones and in fact is the scale that generated the chord in the first place:

[EXAMPLE]

In determining the scale to use over a given chord, a musician may ignore any unaltered extensions and select any scale that contains the corresponding chord tones. For example, the chords C, C6, Cmaj7, and Cmaj9 all suggest the C major scale:

[EXAMPLE]

In general, any major chord suggests the corresponding major scale. For example, Abmaj7 suggests an Ab major scale:

[EXAMPLE]

Recall that the major scale generates minor seventh and dominant seventh chords as well as the major seventh chord that is generated on the first degree. The major scale is an appropriate scale to play over any of the chords generated by that scale. For example, C major may be used over Dm7, which is the ii chord in the key of C:

[EXAMPLE]

The C major scale is also an appropriate choice over G7, which is the V chord in the key of C:

[EXAMPLE]

Thus the C major scale may be used over the ii, V, and I chords in the key of C. In general, for any key, the scale of the I chord can be used over the entire ii-V-I progression in that key. For example, the F major scale can be used over a Gm7-C7-Fmaj7 progression:

[EXAMPLE]

In fact, one can use the major scale of the I chord over an entire progression, as long as that progression is diatonic:

[EXAMPLE]

When non-diatonic chords occur, one can try to analyze them in terms of some major key, and switch to the scale of that key:

[EXAMPLE]

This approach, which I will call the diatonic approach because it uses only the notes diatonic to the key, was used almost exclusively until the bebop era. After that, many musicians began using a different approach, especially in modal music. Instead of playing one scale over a group of chords, these musicians would change scales with every chord. This I will refer to as the modal approach.

Note that the modal approach can be used in tonal music, even in diatonic music. As a trivial example, when playing a C major scale over a ii-V-I in C major, a musician thinking modally will prefer to conceptualize the C major scale as starting on D and G respectively when playing over Dm7 and G7 chords. The resulting scales are called D dorian and G mixolydian:

[EXAMPLE]

These scales all share the same notes, but they have different roots. Scales that have this property are called modes. The major scale is sometimes called the parent of the other modes. The modes of a scale are numbered according to the degree of the parent scale on which they begin. The dorian mode is the second mode of the major scale - the mode starting on the second degree of the major scale. It is an appropriate choice for minor seventh chords built on the root of that mode. The mixolydian mode is the fifth mode and is an appropriate choice for dominant seventh chords built on the root of that mode.

For example, the G dorian mode is generated by starting an F major scale on its second degree and can be used over Gm7 chords wherever they occur:

[EXAMPLE]

The C mixolydian mode is generated by starting an F major scale on its fifth degree and can be used over C7 chords wherever they occur:

[EXAMPLE]

When using this approach, one starts with the chord symbol, then chooses an appropriate scale to use over it. So, for instance, if a progression contains an Bm7 chord, then one could use the B dorian mode over that chord. Working backwards, we note that B is the second degree of the A major scale, so the B dorian mode is generated by starting an A major scale on its second degree:

[EXAMPLE]

One could use this scale over any Bm7 chord, regardless the key the original progression happens to be in. If the key is anything other than A major, then the resulting scale will contain notes that are not diatonic to the key, and this is where this method produces different results than the earlier diatonic approach. For example, a musician playing diatonically would be likely to use G major over the Bm7 chord in the following progression, which is in the key of G, whereas a musician playing modally would be likely to use B dorian, which contains two notes not found in G major:

[EXAMPLE]

Similarly, if you see an Eb7 chord, you might use the Eb mixolydian mode, which, working backwards, turns out to be the fifth mode of the Ab major scale. One could use this scale over any Eb7 chord, regardless of the key of the original progression:

[EXAMPLE]

All of the modes of the major scale are used in jazz. Note the natural minor scale was already introduced as using the notes of the major scale but starting on the sixth degree. Thus it is the sixth mode of the major scale. Like the dorian mode, it may be used over minor chords:

[EXAMPLE]

The remaining modes of the major scale are discussed in the chapter on jazz scales. In classical theory, the major and minor scales are the only modes in common use. The remaining modes are often referred to as the Greek or church modes and are treated mostly as curiosities. In jazz, however, most musicians who learned since the 1950's know these modes well, as well as many other scales that other musicians have usually never even heard of.

Note that one can learn chord/scale relationships either using modes directly or by relating them back to their respective parent scales. For example, one can choose to remember that G7 implies G mixolydian or that it implies the parent C major scale. The latter approach requires learning fewer scales - one need know only the major scales, not all of their modes. However, one must remember or be able to determine which major scale to use with each chord. For example, over Eb7 it is the Ab major scale. This approach becomes more awkward when there is more than possible scale that can be used over a given chord. For example, we have already seen the G mixolydian mode used over a G7 chord. Now, consider the G lydian dominant scale, which may also be used over G7. This scale may also be thought of as the fourth mode of the D melodic minor scale:

[EXAMPLE]

In order to use the technique of relating each mode back to its parent scale, one would have to know that the scales that may be used over G7 are C major or D melodic minor. It seems more straightforward to me to simply learn these scales as G mixolydian and G lydian dominant. Thus, we will tend to use this approach in our presentation.

As we observed in the above examples, there may be several appropriate scales for each chord. Some of these scales may be more colorful than others. For example, either of the scales in the preceding example may be used over a G7 chord, as they both contain the root, third, and seventh of the chord. The lydian dominant provides more color in the form of the raised fourth, however:

[EXAMPLE]

An even more colorful scale is the following, called the HW diminished scale:

[EXAMPLE]

While the possible scale choices are suggested by the function of the chord, a musician chooses between the available scales based on the colors he is trying to achieve. This is discussed further in the unit on Improvisation.

Once a musician has chosen a scale for each chord, he can then invent melodies that use notes from the selected scales. For example, consider the following progression:

[EXAMPLE]

A musician might select the following scales:

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He might then improvise the following melody:

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This process is discussed further in the following section.

Regardless of whether he is using a diatonic or modal approach, the improvisor should try keep in mind the function and resolution of each chord while improvising. For instance, when improvising diatonically, one should probably not be playing the same melodies over a iii-vi-IV progression as a ii-V-I:

[EXAMPLE]

Conversely, when improvising modally, one should see patterns such as ii-V-I and try to honor those in improvised melodies. The melodies one plays over a dominant seventh chord that resolves to its respective tonic should probably differ from the melodies one plays over a dominant seventh chord that is serving some other function, like the IV chord in a blues:

[EXAMPLE]

These considerations can affect the choice of scales to use with a given chord, as well as what one plays in that scale. For example, in a major key, the ii-V-I progression can be played using the scale of the I chord, as described above:

[EXAMPLE]

The same progression can also be played with scales that contain significant differences:

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The scales used in the first example allow the improvisor to play a relatively simple melody over the entire progression:

[EXAMPLE]

The scales used in the second example allow the improvisor to create more tension and release within the melody:

[EXAMPLE]

Both approaches are valid. It is up to the improvisor to decide how he wants his lines to sound.

Tension can be created by deliberately choosing a scale that is not related to the chord. The further removed the scale is from the chord, the more tension that is created. One particularly common device is to use a scale of the same type as the expected scale, but with a root a half step away from the expected one. This is called sideslipping. For example, C dorian would normally be used over Cm7:

[EXAMPLE]

Instead, however, a musician might make use of C# or B dorian:

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Note that the interval of a half step is five points away on the circle of fifths:

[EXAMPLE]

This creates a great deal of tension, which is easily resolved by going back to the expected scale a half step away. For example:

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In tonal music, the improvisor is free to color the harmonies however he pleases, as long as he honors the functions of the original chords. For example, consider the following improvisation:

[EXAMPLE]

The following improvisation is based on the same progression and the melodic ideas, but it uses scales with different colors:

[EXAMPLE]

In modal or other non-tonal chord progressions function plays a much less important role than it does in tonal music. This is indeed what defines a progression as non-tonal. In this type of music, chords are chosen specifically for their colors. It is therefore usually more important to use the colors suggested by chord symbols in the arrangement.

The association between chords and appropriate scales is the subject of the next chapter. It contains a comprehensive description of dozens of scales in common use by jazz musicians and lists the chords associated with each scale. There are scales to fit most of the chords discussed in the previous chapters, and others besides. Before, going into this, however, we discuss how melodies may be created once a scale is selected.

Copyright 2000 Outside Shore Music
Authored by Marc Sabatella

Using Scales